Harvest mice are extremely active climbers and feed in the stalk zone of long grasses and reeds, particularly around dusk and dawn.

Breeding nests are the most obvious sign indicating the presence of harvest mice.

The harvest mouse is the only British mammal to build nests of woven grass well above ground. Harvest mice have many predators, including weasels, stoats, foxes, cats, owls, hawks, crows, even pheasants and their average lifespan is 18 months.

Harvest mice usually have two or three litters a year in the wild. The young are abandoned after about 16 days.